1. Field of the Invention
This invention relates to a driving assistance system that assists driving of a movable body, a driving assistance method used by the driving assistance system, and an assistance information providing apparatus.
2. Description of Related Art
As is commonly available, vehicles such as automobiles are provided with various assistance apparatuses. These assistance apparatuses detect vehicle information including information based on driving operations by a driver and vehicle speed and traveling environment that is information based on a preceding vehicle and road conditions, and provide vehicles with driving assistance including preventive safety assistance based on the detected vehicle information and traveling environment. Examples of such assistance apparatuses include an anti-lock braking system (ABS) that prevents tires from being locked, a vehicle stability control (VSC) system that prevents a vehicle from skidding, and a collision prevention apparatus. For example, Japanese Patent Application Publication No. 2009-29343 (JP 2009-29343 A) describes an example of a driving assistance system including a plurality of such assistance apparatuses.
The driving assistance system described in JP 2009-29343 A includes a driving assistance apparatus (a preventive safety apparatus such as an ABS or a VSC) and a storage unit that stores a traveling location, a traveling environment, and a vehicle condition at the time of operation of the driving assistance apparatus. The driving assistance system stores the traveling location and the traveling environment together with the vehicle condition when the driving assistance apparatus is operated or when a sensor value acquired from a wheel speed sensor, a yaw rate sensor, or a brake pressure sensor that causes the driving assistance apparatus to operate exceeds a set threshold. Moreover, in this system, traveling locations include a slope, an unpaved road, a curve, a parking lot, and an intersection, traveling environment includes an absolute time, snowfall information, rainfall information, and external temperature, and vehicle conditions include a vehicle speed. As the vehicle is to travel a traveling location stored in the storage unit in a traveling environment and under a vehicle condition which are similar to the stored traveling environment and the stored vehicle condition, the driving assistance system performs driving assistance such as issuing a warning notification to the driver and controlling vehicle deceleration.